Test ID: KBF
Potassium, Body Fluid
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Measurement of serum potassium is used for evaluation of electrolyte balance, cardiac arrhythmia, muscular weakness, hepatic encephalopathy, and renal failure. Potassium should be monitored during treatment of many conditions but especially in ketoacidosis of diabetes mellitus and any intravenous therapy for fluid replacement.
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
Indirect Ion-Selective Electrode (ISE)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube: Sterile container
Specimen Volume: 1 mL
Collection Instructions: Centrifuge to remove any cellular material.
Additional Information: Indicate specimen source.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross reject |
| Lipemia | NA |
| Icterus | NA |
| Other | Spinal fluid |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Body Fluid | Refrigerated | 7 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Potassium (K[+]) is the major cation of the intracellular fluid. Disturbance of potassium homeostasis has serious consequences. Decrease in extracellular potassium is characterized by muscle weakness, irritability, paralysis, fast heart rate, specific cardiac conduction effects that are apparent by electrocardiographic examination, and eventual cardiac arrest.
More than 90% of hypertensive patients with aldosteronism have a hypokalemia (low K[+]). Low K(+) also is common in vomiting, diarrhea, alcoholism, and folic acid deficiency.
Abnormally high extracellular K+ levels produce symptoms of mental confusion; weakness, numbness and tingling of the extremities; weakness of the respiratory muscles; flaccid paralysis of the extremities; slowed heart rate, and eventually peripheral vascular collapse and cardiac arrest. Hyperkalemia may be seen in end stage renal failure, hemolysis, trauma, Addison's disease, metabolic acidosis, acute starvation, dehydration, and with rapid K(+) infusion.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Not applicable
Interpretation Provides information to assist in interpretation of the test results
Plasma K=values less than 3.0 mEq/L are associated with marked neuromuscular symptoms and are evidence of a critical degree of intracellular depletion. K(+) values < 2.5 mEq/L are potentially life-threatening.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
It is important to remember that values determined by direct potentiometry/ion selective electrodes may be slightly higher in specimens with high protein and lipid concentrations than the corresponding serum specimen that is assayed by an indirect potentiometric method.
Ion selective electrodes are selective for the ion is question buy are not absolutely specific. Other monovalent cations may interfere but not in the physiologic range.
Method Description Describes how the test is performed and provides a method-specific reference
Ion selective electrode (indirect potentiometry). The ISE module of the P-Module performs indirect measurement of electromotive force (EMF). The ISE module measures the EMF difference between an ion selective electrode and a reference electrode. The EMF of the ion selective electrode is dependent on the ion concentration of the specimen. The EMF of the reference electrode is constant. The P-Module uses an electronic calculation circuit to convert EMF of the specimen to the ion concentration of the specimen.(Package insert: Boehringer Mannheim ISE. Boehringer Mannheim Corp., Indianapolis, IN, 1997)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Sunday continuously.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
84999 (See CPT Coding in Special Instructions)
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| K_BF | Potassium, BF | 2821-7 |
| FLD18 | Fluid Type | 14725-6 |
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